Scientific Method
What is a hypothesis?
An educated guess or possible explanation that can be tested.
How long does it take Earth to rotate once?
24 hours, causing day and night.
How long does it take the Moon to complete all its phases?
About 29.5 days.
Who discovered gravity?
Sir Isaac Newton.
Which planet is closest to the Sun?
Mercury.
What causes the seasons on Earth?
The tilt of Earth’s axis as it revolves around the Sun.
What is the independent variable in an experiment?
The variable that is changed or tested by the scientist.
How long does it take Earth to revolve around the Sun?
About 365 days or one year.
What causes the different phases of the Moon?
The Moon’s position relative to Earth and the Sun.
What is gravity?
A force of attraction between all objects with mass.
Which planet is known as the Red Planet?
Mars.
When is it summer in the Northern Hemisphere?
When the North Pole is tilted toward the Sun.
What is the dependent variable?
The variable that is measured or observed.
What does Earth’s rotation cause?
Day and night.
When the Moon is completely dark, what phase is it?
New Moon.
How does mass affect gravity?
Objects with more mass have a stronger gravitational pull.
Why is it difficult to make a scale model of the solar system?
Because distances between planets are extremely large compared to their sizes.
When is it winter in the Northern Hemisphere?
When the North Pole is tilted away from the Sun.
What is a control variable?
A factor kept the same in all trials of an experiment.
What does Earth’s revolution cause?
The changing seasons.
When the Moon is completely lit, what phase is it?
Full Moon.
How does distance affect gravity?
The farther apart two objects are, the weaker the gravitational pull.
Which planet is the largest in our solar system?
Jupiter.
Why don’t the seasons occur at the same time in both hemispheres?
Because when one hemisphere tilts toward the Sun, the other tilts away.
Why is it important to repeat an experiment?
To ensure results are reliable and not due to chance.
What direction does Earth rotate?
Counterclockwise (west to east).
What is tidal locking?
When the Moon’s rotation matches its revolution, so the same side always faces Earth.
Why do all planets orbit the Sun?
Because of the Sun’s strong gravitational force.
What does ‘astronomical unit’ (AU) measure?
The average distance from Earth to the Sun.
What season has the most direct sunlight and longest days?
Summer.